Heat a large skillet over medium-high heat for about one minute until it's hot. Add your ground beef and break it into chunks with a wooden spoon as it cooks. Don't panic if it looks wet at first — it'll cook down fast. Let it sizzle for 5-6 minutes until it's mostly browned with just a little pink left.
Drain any excess fat from the ground beef tacos mixture using a slotted spoon if needed. You want just enough fat to coat the bottom of the pan for flavor, not a puddle. This step keeps your tacos from getting greasy, which makes a huge difference.
Add your diced onion to the beef and stir everything together. Cook for 2 minutes while the onion softens slightly and releases its aroma. You'll start smelling that savory goodness that makes everyone walk into the kitchen asking what's for dinner.
Toss in your minced garlic and cook for another 30 seconds, stirring constantly. Don't let it sit without stirring or it'll burn and taste bitter. This is such a small step but it completely transforms the flavor of your ground beef tacos.
Sprinkle in the chili powder, cumin, paprika, salt, and black pepper all at once. Stir everything for about one minute so the spices toast slightly and coat every bit of meat. The kitchen smells amazing right now, I promise.
Add 1/4 cup of water to the skillet and let everything simmer for 2-3 minutes. The liquid helps distribute the spices evenly and keeps the beef moist. Mine always sticks a little to the pan and that's totally fine — those crispy bits add texture.
Warm your corn tortillas in a dry skillet for about 15 seconds per side, or wrap them in a damp towel and microwave for one minute. Top each tortilla with the beef mixture, then add tomatoes, lettuce, and cilantro. Let everyone customize theirs because that's half the fun of ground beef tacos.